In the field of information and communication, the technologies related to the computer field have relied on an electronic circuit using a semiconductor device. The researches for the semiconductor device have been conducted so as to improve the processing ability by fining a line width of a wire printed on a substrate, or increasing the degree of integration.
However, such fining technology according to the top-down method has a limit due to the quantum theoretical influence. For this reason, attentions have recently been attracted to a molecular element (bottom-up method) in which a molecule or a group of molecules are functioned as a device.
In the design and/or construction of the molecular element and/or an electronic circuit using the molecular element, the problems have been arisen in terms how to realize the positioning/alignment of individual molecules, recognition of each molecule, access to each molecular element, wiring for accurately linking between certain molecular elements and forming a circuit, addressing, and the like. It is not practical to construct the complicated electronic circuit by sifting the positions of individual molecules.
Therefore, the researches and studies have been conducted on the method for constructing a simple structure and providing complicated functions by the control method. For example, so-called “cross bar switch,” in which the switching at crossing where nano wires are orthogonally crossed is controlled by the input from the nano wires, is a candidate for a nano device which does not have complicated production process, and researches have been actively conducted thereon (see James R. Heath, Philip J. Kuekes, Gregory S. Snider, R. Stanley Williams, Science vol. 280 (1998)). Expectations for this device are high, as high density devices are easily provided, if arrays formed of the nano wires are constructed at molecular level and in the bottom-up method.
The present inventors et al. have researched for a construction of a wire array structure in which a one-dimensional metal complex chain and a one-dimensional conductive wire formed of a donor or acceptor molecule are aligned, aiming at synthesizing a metal complex integrated structure realizing both a element function and wiring function at the same time by utilizing a self-alignment and/or self-integration of metal complex. Therefore, we have developed various dinuclear metal complexes for use as a building block for the construction of the wire array structure (see International Publication No. WO 03/078384). This dinuclear metal complex realizes switching by crossing molecular chains in the self-forming crystal and/or thin film, and changing electric conductivity of the metal complex chains by the electron transfer at the crossings.
However, in this case, a coupling molecule (conductive wire portion) needs to be introduced separate from the metal complex unit, and the conductive wire is connected with a hydrogen bonding so as to form a metal complex integrated structure using the dinuclear metal complex as a building block. As the metal complex integrated structure is formed from multiple components, the control for alignment may be difficult, or a large conductivity may not be expected.
Moreover, a ligand for forming the dinuclear metal complex is formed of one molecule, and thus the molecular weight thereof naturally becomes large. Therefore, the solubility of the dinuclear metal complex in which a metal is incorporated to the ligand is lowered, and it may be difficult to form a metal complex integrated structure.